The macroecology of infectious diseases: a new perspective on global‐scale drivers of pathogen distributions and impacts

Identifying drivers of infectious disease patterns and impacts at the broadest scales of organisation is one of the most crucial challenges for modern science, yet answers to many fundamental questions remain elusive. These include what factors commonly facilitate transmission of pathogens to novel host species, what drives variation in immune investment among host species, and more generally what drives global patterns of parasite diversity and distribution? Here we consider how the perspectives and tools of macroecology, a field that investigates patterns and processes at broad spatial, temporal and taxonomic scales, are expanding scientific understanding of global infectious disease ecology. In particular, emerging approaches are providing new insights about scaling properties across all living taxa, and new strategies for mapping pathogen biodiversity and infection risk. Ultimately, macroecology is establishing a framework to more accurately predict global patterns of infectious disease distribution and emergence.     

A transgenic plant cell‐suspension system for expression of epitopes on chimeric Bamboo mosaic virus particles

We describe a novel strategy to produce vaccine antigens using a plant cell‐suspension culture system in lieu of the conventional bacterial or animal cell‐culture systems. We generated transgenic cell‐suspension cultures from Nicotiana benthamiana leaves carrying wild‐type or chimeric Bamboo mosaic virus (BaMV) expression constructs encoding the viral protein 1 (VP1) epitope of foot‐and‐mouth disease virus (FMDV). Antigens accumulated to high levels in BdT38 and BdT19 transgenic cell lines co‐expressing silencing suppressor protein P38 or P19. BaMV chimeric virus particles (CVPs) were subsequently purified from the respective cell lines (1.5 and 2.1 mg CVPs/20 g fresh weight of suspended biomass, respectively), and the resulting CVPs displayed VP1 epitope on the surfaces. Guinea pigs vaccinated with purified CVPs produced humoral antibodies. This study represents an important advance in the large‐scale production of immunopeptide vaccines in a cost‐effective manner using a plant cell‐suspension culture system.     

AMPK activation protects cells from oxidative stress‐induced senescence via autophagic flux restoration and intracellular NAD+ elevation

AMPK activation is beneficial for cellular homeostasis and senescence prevention. However, the molecular events involved in AMPK activation are not well defined. In this study, we addressed the mechanism underlying the protective effect of AMPK on oxidative stress‐induced senescence. The results showed that AMPK was inactivated in senescent cells. However, pharmacological activation of AMPK by metformin and berberine significantly prevented the development of senescence and, accordingly, inhibition of AMPK by Compound C was accelerated. Importantly, AMPK activation prevented hydrogen peroxide‐induced impairment of the autophagic flux in senescent cells, evidenced by the decreased p62 degradation, GFP‐RFP‐LC3 cancellation, and activity of lysosomal hydrolases. We also found that AMPK activation restored the NAD⁺ levels in the senescent cells via a mechanism involving mostly the salvage pathway for NAD⁺ synthesis. In addition, the mechanistic relationship of autophagic flux and NAD⁺ synthesis and the involvement of mTOR and Sirt1 activities were assessed. In summary, our results suggest that AMPK prevents oxidative stress‐induced senescence by improving autophagic flux and NAD⁺ homeostasis. This study provides a new insight for exploring the mechanisms of aging, autophagy and NAD⁺ homeostasis, and it is also valuable in the development of innovative strategies to combat aging.     

Small interfering RNA targeting NF-κB attenuates lipopolysaccharide-induced acute lung injury in rats

Background

Veterinary cardiology, especially electrocardiography, has shown major advancements for all animal species. Consequently, the number of ovine species used as experimental animals has increased to date. Few studies have been published on ovine systematic electrocardiography, particularly with respect to lamb physiology and neonatology. This study aimed to standardize the values of normal waves, complexes, and intervals of the electrocardiogram (ECG) in clinically Bergamasca healthy neonatal lambs, used as experimental animals. Serial computerized electrocardiography was performed in 10 male and 12 female neonates on the 1st, 7th, 14th, 21st, 28th, and 35th days of age. The following parameters were analyzed: heart rate and rhythm, duration and amplitude of waves, duration of intervals, and heart electrical axis.

Results

During the first 35 days of life, (1) the sinusal heart rhythm was predominant, (2) there was a progressive decrease in the heart rate and R and T wave amplitude, and (3) a progressive increase in the PR, QT, and RR intervals. Finally, we confirmed that various components of neonatal evolution were more discernible in the augmented unipolar leads (aVF), which we recommend should be preferentially used in future studies. No significant statistical alterations were observed between males and females in relation to the analyzed parameters.

Conclusions

The information assimilated in this study is anticipated to enhance the diagnosis of multiple congenital heart defects in Bergamasca lambs and could be implemented in studies that use ovine species as experimental models.

     

Neuroprotective effects of (E)-3,4-diacetoxystyryl sulfone and sulfoxide derivatives in vitro models of Parkinson's disease

(E)-3,4-dihydroxystyryl aralkyl sulfones and sulfoxides have been reported as novel multifunctional neuroprotective agents in previous studies, which as phenolic compounds display antioxidative and antineuroinflammatory properties. To further enhance the neuroprotective effects and study structure-activity relationship of the derivatives, we synthesized their acetylated derivatives, (E)-3,4-diacetoxystyryl sulfones and sulfoxides, and examined their neuroprotective effects in vitro models of Parkinson’s disease. The results indicate that (E)-3,4-diacetoxystyryl sulfones and sulfoxides can significantly inhibit kinds of neuron cell injury induced by toxicities, including 6-OHDA, NO, and H₂O₂. More important, they show higher antineuroinflammatory properties and similar antioxidative properties to corresponding un-acetylated compounds. Thus, we suggest that (E)-3,4-diacetoxystyryl sulfones and sulfoxides may have potential for the treatment of neurodegenerative disorders, especially Parkinson’s disease.     

The Remediation of Chromium (VI)-Contaminated Soils Using Microbial Fuel Cells

Chromium (VI) is a priority pollutant in soil and water and poses serious threats to the environment. Microbial fuel cells (MFCs), as a sustainable technology, have been applied to treat heavy-metal-contaminated wastewater. To study MFC application in soil remediation, red clay soil and fluvo-aquic soil were spiked with Cr(VI) and packed into a cathode chamber of MFCs, which were then operated at external resistances of 100 and 1000 Ω for 16 days, with open circuit condition as a control treatment. After the operation, the concentration of dissolved Cr(VI) in supernatant and total Cr(VI) in soil was decreased. Soil type and external resistance significantly affected the current, removal efficiency of Cr(VI), and cathode efficiency. Reducing external resistance improved the removal efficiency. The red soil generated a higher current of MFCs, but showed a lower removal efficiency and cathode efficiency than fluvo-aquic soil, implying that the red soil may contain more electron acceptors that competed with Cr(VI) reduction reaction. Our study demonstrated that MFC-based technology has the potential to remediate Cr(VI)-contaminated soil; the efficiency varied between soil types and can be improved with high current.